The present invention is a method for operating a computer system to
retrieve information from a computer database. This method decomposes
documents from the database into subdocuments and then inverts the
database. Also, a query for retrieving documents from a database is
decomposed into terms. The subdocuments from the inverted database and the
terms from the query are then used to compute a score that indicates a
quantitative relation between terms in the query and the subdocuments. The
resulting list of the subdocuments and their scores is then reorganized
into a heap form. The highest ranking subdocument is then selected by the
computer and the text associated with this subdocument is displayed. The
remainder of the subdocument score list is concurrently reheapified.